Tool for testing the hardness of materials



F. C. FAIRHOLME, W. H.-HATFIELD AND G. STANFIELD.

TOOL FOR-TESTING THE HARDNESS OF MATERIALS.

APPLICATION FILED AUG.2I, 1920.

1,376,413. Patented May3,1921.

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FREDERICK C. FAIRHOLME, WILLIAM HERBERT HATFIELD, AND GEORGE STANFIELD,OF SHEFFIELD, ENGLAND, ASSIGNORS TO FIRTH STERLING STEEL COMPANY, OFMOKEESPORT, EENNSYLVANIA, A CORPORATION'OE PENNSYLVANIA.

TOOL FOR TESTING THE HARDNESS OF MATERIALS.

Specification of Letters Patent.

Patented May 3, 1921.

Application filed August 21, 1920. Serial No. 405,199.

full, clear, and exact description, reference being had to theaccompanying drawing, forming part of this specification, in which thefigure is a side elevation, partially in section, of a tool embodyingthe present invention.

The present invention relates to tools for testing the hardness ofmaterials and more particularly to a portable tool preferably in theform of tongs or pincers for testing the hardness of metals by theBrinnell system. As shown in the drawing, our tool or device preferablyis of the above type in which a relatively high pressure is developed between the impression ball and the anvil by means of a helical U shapedor other suitable spring fitted between the handles of the de-' 'vice,and having manually operable means for bringing the spring into actionto force the work engaging aws together.

Referring to the embodiment of the invention illustrated in the drawing,we form one of the handles a of the pincer-like device with an inwardlycurved bow a to the short free end of which we secure one member 6' ofthe spring 6, which thus lies in the gap between the two handles a and0, the bow end of the spring 6 being toward the pivot of the device. Ator near the end of the other or straight handle 0 of the device, wesecure a U strap or bridle d in such a manner that it embraces bothhandles a and c, and projects beyond the outer edge ofthebowended sidea. Pivoted within this projecting end of the bridle d, is a hand lever 6with a cam shaped end 6', adapted to bear upon the head of a pin orspindle f passing through the bow-ended handle a, through the twomembers 5 and b of the spring b and into a guide hole in the free end ofthe bow at. The pin 7 is threaded for the whole or part of its lengthand a nut g is placed upon such threaded portion, so that it engages theouter face of the free member I).

of the spring b.

Through the fast end of the bridle d, we

place a screwed limiting stop h, with a lock nut h, and on the innerside of the straight handle 0, we secure a flat strip or other suit- 7able form of spring 0, which engages with the bow end a of the handle a,and is for the purpose of separating the handles a and 0 andconsequently also the jaws i and j of the device after each operation.

Of the two jaws, one 7' is fitted with a hardened impression ball [acharacteristic of Brinnell machines and the other 2' is fitted with ascrew adjusted anvil Z of suitable shape, with a locking nut Z;

The spring 5 before referred to, has its members 6' and 6 under acompression of any predetermined intensity-when placed in position, andwhen the device is at rest, the two oppositely acting forces in thespring are balanced or neutralized by pressing against the two sides aand a of the bowended handle, in one case the nut g on the sliding pin 7is interposed between the spring and the side of the handle a.

The operation of our improved device is as follows:

The article to betested, such as a strip of cutlery steel, is firmlyheld between the impression ball 70 and the anvil Z in the jaws. Thehand lever e is then depressed, the cam end 6' of which causes amovement of the bears against the free member I)? of the spring I), andthus relieves the pressure of that member on the inner face of thebowended handle a; The result of this, is that the energy in thatparticular member of the spring then acts through the nut 9, pin f andcam end 6 of the hand lever e, on to the pivot pin d in the bridle d,thus tending to push the latter outward, and in so doing, it of coursemoves the handle 0 to which the bridle d is attached, and in consequencealso, the jaw j connected to such handle is moved inward toward itsfellow.

Simultaneously, with the before described action. the effect of removingthe pressure of the free member 6 of the spring. 6 from the inner faceof bow-ended handle a is to allow the other member 6 of the spring 6 toexert a predominating influence on the free end a of the bow of thehandle (1, thus causing the said handle a to move inward, with aconsequent movement of the connected jaw i, which is thus moved towardits fellow.

The result of the two jaws 2' and j moving toward each other under theimpelling 1nfluence of the powerful spring Z2, is to cause the testpiece to be'tightly nipped between pressure exerted between the jaws andi It is to beunderstood that the presentinvention isnot limited to itspreferred embodiment as above described, but may be otherwise embodied.within the scope of the following claims.

We'claim:

1. A tool for testing the hardnessof ma-' terials, comprising workengaging jawspa spring, meansior normally holdmg the spring under strainandimanuallyoperable means for causing the force of the spring to beapplied to the jaws and thereby force them toward each other withspringpressure, substantially as described. a p

2. A tool for testing the hardness of materials, comprising pivoted workengaging jaws and their handles, a spring mounted between the handles,and relatively stationary abutmentsnormally holding the spring understrain and manually operable means for causing the force of the springto be applied to the handles and thereby force the jaws toward eachother with spring pressure, substantially as described.

3. A tool for testing the hardness of materials, comprising pivoted workengaging jaws and their handles, a spring, relatively stationaryabutments against which the force of the spring is normally expended andmanually, operable means for transferring the force of the spring to thehandles to thereby force the jawstoward each other with spring pressure,substantially as de'-.

scribed.

4. A tool for testing the hardness of materials, comprising pivoted workengaging jaws and their handles, one of which handles has a bowed end, aspring mounted under compression within said bowcd'end and norm lyexerting its force againstthe opposite sides of the how, a manuallyoperable means ior transferring the force of the spring from the bowtoth other handle to force the aws toward each other wlth springpressure, substantially as described.

5. A tool for testing the hardness of ina-' spring and having a nutwhich bears upon one end of the springysubstantially as de-' scribed.GJA tool for testing the hardness of materials, comprising pivoted'workengaging aws and then handles, one of which han-- dles has a bowed end,a spring mounted under compression within the said bowed end andnormally exerting its force against the opposite sides of the bow, amanually operable means for transferring the force of the spring to theother handle, comprising a bridle embracing the endsfof the handles, apin extending through the bowed handle and the spring, a cam ended leverpivoted on the bridle and engaging oneend of the pin. and anut threadedon the pin and engaging one end of the spring, substantial1y asdescribed. V v y In testimony whereof, we have hereunto set our vhands.

FREDERICK C. FAIRHQLME.

WILLIAM HERBERT HATFIELD. GEORGE STANFIELD.

